Concrete construction creates
unique moisture challenges
Malta’s modern concrete-frame apartments present a different set of humidity challenges. Thermal bridges at slab edges and column junctions create cold spots where condensation forms. Combined with airtight construction and inadequate ventilation, these buildings trap moisture and create persistent indoor humidity problems.
Understanding the Problem
Modern Maltese apartments are built very differently from traditional homes. Concrete frame construction with block infill creates thermal bridges — areas where heat escapes more easily — at slab edges, column junctions and window reveals. These cold spots are typically 3-5 degrees colder than the surrounding wall surface, making them the first place where condensation forms. At the same time, modern apartments are designed to be airtight for energy efficiency, but without mechanical ventilation, the moisture generated by occupants has nowhere to go. A family of four produces approximately 10-12 litres of water vapour per day through breathing, cooking, showering and drying clothes. In an airtight apartment with no ventilation strategy, this moisture accumulates until it condenses on the coldest surfaces. The result is a persistent humidity problem that affects health, comfort and building durability. The solution requires a systems approach: mechanical ventilation with heat recovery to remove moisture efficiently, combined with breathable internal insulation to eliminate cold surfaces and allow any residual moisture to pass through harmlessly.
How It Happens
Concrete construction creates thermal bridges at structural elements where insulation is interrupted.
These thermal bridges are 3-5°C colder than surrounding walls, creating cold spots.
Airtight design prevents natural ventilation, trapping moisture generated by occupants inside.
When moist air contacts cold thermal bridges, condensation forms — typically at corners and junctions.
Persistent damp creates ideal conditions for mould growth, which spreads and affects air quality.
Warning Signs to Watch For
- Mould at wall-ceiling junctions and corners
- Condensation on windows and cold walls
- High indoor relative humidity (>60%)
- Damp feeling in bedrooms and bathrooms
- Recurring mould despite cleaning
Why This Matters
Modern apartment humidity is a systemic problem that affects thousands of Maltese families. The health impacts of persistent mould exposure are well-documented, including asthma, allergies and chronic respiratory conditions. Beyond health, moisture damage to finishes and structure reduces property value and creates ongoing maintenance costs. As Malta continues to build modern apartments, addressing humidity at the design and construction stage is essential — but for existing buildings, retrofit solutions are available and highly effective.
Case Study: Valletta Townhouse Restoration
Location
St. Julian's, Malta
Challenge
A 2018-built penthouse apartment had persistent mould in the master bedroom and bathroom, despite being only 6 years old. The owners had tried dehumidifiers and anti-mould paint with no success. Indoor humidity consistently exceeded 70%.
Result
Indoor humidity reduced to 45-50% within 2 weeks. All mould growth stopped. The apartment now maintains comfortable humidity levels year-round with minimal energy cost. The owners report significantly improved sleep quality and no more musty smells.
Our Solution
Installation of Ambientika decentralised HRV units in bedroom and bathroom. Application of Renopor breathable internal insulation system on north-facing external wall. Replacement of impermeable paint with breathable mineral finish throughout.
The Right Solution
Internal Insulation + HRV — a system-based approach that addresses the root cause, not just the symptoms.